Dihydric phenols, hydroquinone and resorcinol for example, are produced according to known processes by the rearrangement of dialkyl benzene dihydroperoxides. Production of resorcinol by rearrangement of m-diisopropylbenzene dihydroperoxide and the production of hydroquinone by the rearrangement of p-diisopropylbenzene dihydroperoxide are well known. In each of these latter processes, a dihydric phenol product and acetone byproduct are produced.
The separation of the hydroquinone or resorcinol from the byproduct acetone and from impurities has been the subject of long and continuing interest. Both hydroquinone and resorcinol, for example, have been recovered by azeotropic distillation from the reaction mixture following addition of a material which forms a low boiling azeotrope with the dihydric phenol of interest. Chlorinated biphenyl, alpha-chloronaphthalene, and other materials which are inert to the dihydric phenol and which form azeotropes of suitable vapor pressure have been used.